Demolition /razing is the tearing down of buildings and other structures. It is a kind of deconstruction, it includes taking buildings apart while preserving the useful elements which can be reused. Building demolition is a very technical work to be done which requires highly professional people to perform it. So, for careful and professional building demolition make a call at Malik technical.
For the sake of small building’s demolition such as two or three story houses, demolition is done simply, it is done by using heavy machines such as cranes, excavators or bulldozers. Larger Building demolition requires the use of a wrecking ball which has to be handled carefully and professionally.
Pre-building demolition information
The degree and detail of details and surveys needed for pre-demolition should be proportionate to the project and may include:
- Survey of asbestos demolition
- Structural hazards or risks
- Hazardous materials
- Desk studies which involves the historic use of buildings, land, contamination etc.
- Building regulation.
- Party wall e.g Act notices
- Site finish is required
- Pre-construction information
Planning permission for building demolition
Building demolition includes notice to be sent to the municipal authority for the purpose of deciding if prior permission is necessary for demolition methods where buildings are greater than 50 cubic metres and for walls or gates.
For the removal of unlisted buildings in protected areas, planning permission is necessary and listed building consent is required for the demolition of some section of a listed building.A screening opinion can be sought from the local authority to decide if a full Environmental Impact Assessment (EIA) is needed whether demolition activities may have an environmental impact.
General Building demolition procedures
Here are some general demolition procedures:
- Compound web and security set-up
- Pre-demolition invasive surveys (such as; asbestos survey for demolition, structural survey, hazardous materials surveys, etc)
- Utility separation and metre replacement
- Utility disconnections
- Removal of asbestos (in accordance with the Control of Asbestos Regulations)
- Soft strip (taking the structure back to construction materials including the removal of windows and door frames)
- Demolition of superstructures with special steps such as requirement for constraints, such as de-building or security of adjacent structures
- Production of new superstructures
- Demolition of the slab and base
- Arisings processing
- The site ends as needed
Methods for building demolition
Demolition procedures can range from one destructive explosion to cautious, piece-by-piece dismantling, but either approach must be secure for the demolition team and the nearby structures and public areas in a busy urban environment. Methods for building demolition are here:
- Implosion
It is said to be the most dramatic way for building demolition. Several explosives are used to knockout a building’s primary vertical supports which results in the fall down of the building from the inside out.The location of the explosive charges and the detonation sequence are necessary for a safe and secure demolition. Implosion is usually done for the large buildings in urban areas.
Blaster teams review a full collection of structural blueprints for a good demolition to locate the key building elements and decide if any locations need to be blasted in addition to those listed on the blueprints.The sort of explosives to be used, where to locate them in the house, and how to schedule their detonation are then determined.
- High reach arm
High reach arm is alternative to implosion and is done for the buildings reaching of more than about 66 feet. This procedure requires a base machine fitted with a long demolition arm made of three parts or a telescopic boom, such as an excavator. At the end of the arm, a demolition instrument such as a crusher, shears, or a hammer is attached and used to break up the structure from the top down. The large pieces of the structure are removed by the machine and the pieces are broken down by the special grounds and sorted for disposal.
For reinforced concrete, masonry, steel, and mixed-material structures, high-reach arm demolition is used and is known to be better for dismantling tall buildings than conventional wrecking ball demolition.
- Wrecking ball
Wrecking ball demolition or ball demolition is one of the oldest and common methods of building demolition which is typically used for concrete and other masonry structures. The wrecking ball is hanging from a crane or other heavy machinery on a wire, weighing up to 13,500 pounds. The ball is either lowered into the structure or swung onto it, simply smashing the structure with repeated blows.
Wrecking ball building demolition must be done by highly professional and qualified crane operators. Smoothness is crucial in managing the ball’s swing since the missed target will tip or overwhelm the crane.The scale of the structure that can be destroyed using this procedure, including proximity to power lines, is constrained by the size of the crane and the work space. A great deal of dust, friction, and noise is created by wrecking ball demolition.
- Selective demolition
Selective demolition is also known as strip-out and is gaining attention because it helps contractors to reuse or recycle the materials of the house.Selective internal and external removal of timber, brick, metal and concrete allows modern buildings to be recycled and used in the future, combining the old with the new.In a safe and cost-effective technique, the main purpose of this approach is to recover the full amount of primary (reusable) and secondary (recyclable) material.The process, however, is labor-intensive and can be very difficult to achieve for light-framed buildings in a timely and economical manner.
Material disposal
Generally, buildings turned over for demolition include hazardous waste, landfill waste and recyclable materials. For all demolition projects, the best practise of using site waste management plans will ensure that the optimal recycling chains are in operation. By turning over vacant buildings and seeking fresh uses for furniture and appliances, clients will help.
Building demolition creates goods suitable for building with the general rule that a grade lower than its original state should be called a recycled material.So, for example, crushed structural concrete may be used as blinding, although it may be possible to achieve structural quality concrete with complete treatment and a built mix. At present, reaching 95 percent mass building recycling, or even more for certain structures, should be realistic for a professional contractor.Materials for WRAP protocols with Environment Agency approval should be given. For volumes in excess of 3,000 cubic metres, crushing on site is realistic.
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